U.S. patent application number 11/940112 was filed with the patent office on 2009-05-14 for aircraft flight display with a non-linear pitch scale.
Invention is credited to James Mitchell Brannen, John Russell Jorgensen, Patrick Krohn, Joachim Laurenz Namier, Cheng Wang.
Application Number | 20090121901 11/940112 |
Document ID | / |
Family ID | 40623202 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090121901 |
Kind Code |
A1 |
Namier; Joachim Laurenz ; et
al. |
May 14, 2009 |
AIRCRAFT FLIGHT DISPLAY WITH A NON-LINEAR PITCH SCALE
Abstract
A display image for use in an aircraft is produced in response
to receiving aircraft location, heading, altitude, and pitch data.
The location and heading data are employed to access a
topographical database and obtain terrain information for a region
on the earth's surface ahead of the aircraft. A terrain image is
produced from the terrain information and a non-linear pitch scale
is superimposed over the terrain image. The non-linear pitch scale
corresponds to the relationship of the aircraft pitch and the
terrain image. Additional data designating other aircraft
operational parameters, such as speed and altitude, are depicted by
graphical objects. The terrain image, the non-linear pitch scale,
and the graphical objects are combined into the display image. The
terrain image and the non-linear pitch scale move in the display
image in response to changes in the pitch of the aircraft.
Inventors: |
Namier; Joachim Laurenz;
(Ascona, CH) ; Brannen; James Mitchell; (Flowery
Branch, GA) ; Jorgensen; John Russell; (Lynnwood,
WA) ; Wang; Cheng; (Bothell, WA) ; Krohn;
Patrick; (Bellevue, WA) |
Correspondence
Address: |
QUARLES & BRADY LLP
411 E. WISCONSIN AVENUE, SUITE 2040
MILWAUKEE
WI
53202-4497
US
|
Family ID: |
40623202 |
Appl. No.: |
11/940112 |
Filed: |
November 14, 2007 |
Current U.S.
Class: |
340/975 |
Current CPC
Class: |
G08G 5/0021 20130101;
G01C 23/00 20130101; G08G 5/0086 20130101 |
Class at
Publication: |
340/975 |
International
Class: |
G01C 23/00 20060101
G01C023/00 |
Claims
1. A method for producing an display image for a display screen in
an aircraft which is proximate to a surface of the earth, the
method comprising: receiving information indicating location and
pitch of the aircraft; using the location of the aircraft to access
a topographical database and obtain terrain information regarding a
region on the surface of the earth; producing a terrain image from
the terrain information; associating a non linear pitch scale with
the terrain image; and combining the terrain image and the non
linear pitch scale into the display image.
2. The method as recited in claim 1 further comprising: determining
a heading of the aircraft; and further using the heading of the
aircraft to access a topographical database and obtain terrain
information regarding a region on the surface of the earth.
3. The method as recited in claim 1 wherein orientation of the
terrain image and the non linear pitch scale in the display image
corresponds to the pitch of the aircraft.
4. The method as recited in claim 1 wherein the terrain image and
the non linear pitch scale are altered in the display image in
response to changes in the pitch of the aircraft.
5. The method as recited in claim 1 wherein the topographical
database contains Shuttle Radar Topography Mission (SRTM) digital
topographic data.
6. The method as recited in claim 1 further comprising presenting
the display image on the display screen of the aircraft.
7. The method as recited in claim 1 further comprising: receiving
data designating operational parameters of the aircraft; producing
graphical objects depicting the operational parameters of the
aircraft; and incorporating the graphical objects into the display
image.
8. The method as recited in claim 1 further comprising receiving
information indicating altitude of the aircraft, and using the
altitude to produce the a terrain image.
9. A method for producing a display image for a display screen of
an aircraft that is proximate to a surface of the earth, the method
comprising: receiving data indicating location, altitude, heading,
and pitch of the aircraft; using the location and heading of the
aircraft to access a topographical database and obtain terrain
information regarding a region on the surface of the earth;
producing a terrain image from the terrain information and the
altitude; associating a non-linear pitch scale with the terrain
image; receiving data designating operational parameters of the
aircraft; producing graphical objects depicting the operational
parameters of the aircraft; and combining the terrain image, the
non-linear pitch scale, and the graphical objects into the display
image.
10. The method as recited in claim 9 wherein orientation of the
terrain image and the non-linear pitch scale in the display image
corresponds to the pitch of the aircraft.
11. The method as recited in claim 9 wherein positions of the
terrain image and the non linear pitch scale in the display image
are altered in response to changes in the pitch of the
aircraft.
12. The method as recited in claim 9 wherein the topographical
database contains Shuttle Radar Topography Mission (SRTM) digital
topographic data.
13. The method as recited in claim 9 further comprising displaying
the display image on the display screen of the aircraft.
14. A system which produces an display image in an aircraft that is
proximate to a surface of the earth, the system comprising: at
least one data port for receiving information designating location
and pitch of the aircraft; a topographical database containing
terrain information regarding the surface of the earth; and a
display processing engine which accesses the topographical database
in response to location information received by the at least one
data port and obtains the terrain information for a region on the
surface of the earth, and which produces a terrain image from the
terrain information, the display processing engine further
associating a non linear pitch scale with the terrain image, and
combines the terrain image and the non-linear pitch scale into the
display image.
15. The system as recited in claim 14 wherein the display
processing engine orients the terrain image and the non-linear
pitch scale in the display image to correspond to the pitch of the
aircraft.
16. The system as recited in claim 14 wherein the display
processing engine alters positions of the terrain image and the
non-linear pitch scale in the display image in response to changes
in the pitch of the aircraft.
17. The system as recited in claim 14 wherein the topographical
database contains Shuttle Radar Topography Mission (SRTM) digital
topographic data.
18. The system as recited in claim 14 further comprising a display
screen on which the display image is displayed.
19. The system as recited in claim 14 wherein the at least one data
port further receives data designating operational parameters of
the aircraft; and the display processing engine produces graphical
objects depicting the operational parameters of the aircraft, and
incorporates the graphical objects into the display image.
20. The system as recited in claim 14 wherein the at least one data
port further receives information designating altitude of the
aircraft; and the display processing engine employs the altitude of
the aircraft to produce the terrain image.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to display systems for
aircraft, and more particularly to the aircraft's primary flight
display.
[0005] 2. Description of the Related Art
[0006] The flight deck of an aircraft has several displays that
present information about the aircraft operation and flight
conditions. These displays are employed to monitor various events
in real-time and to provide a visual indication of such events in
graphical form thereby allowing an observer to make decisions based
on the occurrence of one or more specific events in particular
relationship to each other. One of the key instruments used by
aircraft pilots is a display commonly referred to as a Primary
Flight Display, or PFD, used to operate and/or maneuver aircrafts
during take-off; flight and landing. When the aircraft is in
flight, the PFD provides numerous information about the aircraft,
such as its heading, roll (the angle of wings relative to
horizontal), and pitch (the degree to which the aircraft nose is
pointing up or down relative to the horizontal. The graphics
depicted by the PFD are arranged in a standard format to allow a
pilot to quickly locate particular information by focusing in on
the specific part of the display screen to which the information
has been assigned.
[0007] FIG. 1 depicts a standard graphic and textual information
arrangement on a PFD. Note that textual information is included
with other graphical information to allow the pilot of the aircraft
to determine the status of various sensor readings being provided
to the aircraft while in flight. The sensor readings present
information from different sources which are converted to graphical
signals for display on the PFD.
[0008] The depiction of the Primary Flight Display in the drawings
has been annotated to identify the types of displayed information
used by the pilot while the aircraft is in flight, taking off or
landing. The "inverted V" shown at generally the center of the
display represents the aircraft in reference to the horizontal. The
"Zero Roll Reference" is a reference point for determining how much
"roll" the aircraft is experiencing during flight with a "Roll Bug"
depicting the degree that the aircraft is deviating from a zero
roll orientation. The roll is a measure of how much the aircraft is
rotated about its longitudinal axis (i.e., the axis that is
oriented lengthwise of the aircraft). Also, various speeds of the
aircraft are displayed. Specifically a speed tape on the left edge
of the PFD indicates the forward speed of the aircraft and an
arcuate scale in the lower right corner provides a vertical speed
indication. An altitude indicator displays the present altitude in
relation to a desired altitude for the aircraft. A heading tape
along the bottom edge of the PFD presents information regarding
heading of the aircraft and it deviation from a desired
heading.
[0009] A pitch ladder designates the pitch of the aircraft in
degrees with respect to horizontal. The standard PFD has the region
below the horizontal uniformly colored brown to correspond to earth
and the region above the horizontal uniformly colored blue to
correspond to the sky. Pitch is rotation around a transverse axis
of the aircraft parallel to the wings. The pitch ladder has a
linear scale with five degree increments up and down indicated by
equally spaced L-shaped markers with the markers for 10 and 20
degrees being labeled with those numerals. The pitch ladder moves
vertically on the display with the current pitch of the aircraft
being indicated by alignment of a point of the ladder with the apex
of the stationary inverted V-shaped aircraft symbol. In the
exemplary indication on the PFD in FIG. 1, the aircraft is level at
zero pitch, however if the nose of the aircraft tilts up the
horizontal line at zero pitch drops below the aircraft symbol and
the pitch ladder also moves downward on the PFD until the degree
indication corresponding to the actual pitch is laterally aligned
with the apex of the aircraft symbol.
[0010] Various other information can be provided by the PFD.
SUMMARY OF THE INVENTION
[0011] A method produces an display image for a display screen of
an aircraft which involves determining the location and the pitch
of the aircraft. The location is employed to access a topographical
database that contains data regarding the contour of the surface of
the earth, such as for example Shuttle Radar Topography Mission
(SRTM) digital topographic data representing elevation data on a
near-global scale. Information obtained from the topographical
database regarding a region on the surface of the earth ahead of
the aircraft is used to produce a terrain image. A non-linear pitch
scale then is associated with the terrain image. The terrain image
and the non-linear pitch scale are combined into the display
image.
[0012] Preferably, orientation of the terrain image and the
non-linear pitch scale in the display image corresponds to the
pitch of the aircraft. That orientation is altered in response to
changes in the pitch of the aircraft. In another aspect of this
method, other operational parameters of the aircraft is received
from which graphical objects depicting those operational parameters
of the aircraft are produced and incorporated into the display
image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows an annotated version of a conventional primary
flight display graphic;
[0014] FIG. 2 is a block diagram of the display generation system
according to the present invention;
[0015] FIG. 3 is an improved display device depicting a primary
flight display with a terrain underlay image and a non-linear pitch
scale; and
[0016] FIG. 4 illustrates the primary flight display when the
aircraft is pitching downward.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides a display generation system
and method for an aircraft. The display generation system has
access to a topographical database containing information about the
contour of the earth's surface and image databases containing image
data. That collective information is used to produce an underlay
image depicting terrain of the earth over which the aircraft is
flying. The underlay terrain image is displayed simultaneously with
an overlay image containing information related to the aircraft's
current operational status as provided by one or more data sources,
such as an navigational system. The combination of the underlay and
overlay images produces a combined display signal that represents a
graphic image and/or video picture that typically is displayed on a
monitor in the aircraft flight deck.
[0018] With initial reference to FIG. 2, a display system 100 for
an aircraft comprises a display generation system 101 and a display
device 108, which preferably is a video monitor having an LCD, LED
or CRT display screen. The display generation system 101 and method
of the present invention are being described in the context of a
PFD, however the concepts may be used with other types of aircraft
displays.
[0019] Display generation system 101 includes a display processing
engine 106 that obtains information from one or more image database
102 and a topographical database 104, as well as receiving external
information from various data sources via data ports 116 and path
118. The collective information so obtained is employed to produce
graphical and/or video images for the display device 108. The
display processing engine 106 may be any device or system, such as
a microcomputer or image processor, that is able to obtain
information regarding images and generate display signals for the
images. The term "image" as used herein comprises either and
arrangement of one or more graphic images, a video image, or any
combination thereof. The signal paths connecting the various
components can be any well known media typically used to transmit
and/or receive signals. Therefore, the paths can be, for example,
copper or other electrical wire, coaxial cables, fiber optic
cables, and waveguides.
[0020] The topographical database 104 contains data regarding the
contour of the surface of the earth, for example Shuttle Radar
Topography Mission (SRTM) digital topographic data representing
elevation data on a near-global scale. Moreover, different
perspectives of the various objects, geographical features, or
scenery can also be stored in the topographical database 104. The
display processing engine 106 receives data via external data ports
116 from the on-board navigational system, designating the location
and heading of the aircraft. The present location, altitude, and
heading data are employed to access the topographical database 104
to obtain contour information for an area in front of the aircraft.
Instead of using the heading of the aircraft, the bearing of the
aircraft with respect to a topographical feature near the
aircraft's present location could be employed to obtain contour
information for an area in front of the aircraft for image
construction purposes. Therefore the use of the term heading herein
also encompasses the use of bearing information. The display
processing engine 106 uses that topographic contour information to
construct a shaded, color underlay image depicting the earth's
terrain ahead in the aircraft's flight path, which underlay image
is provided as a first display signal. The terrain image changes
periodically as the aircraft moves forward over the terrain and the
frequency at which the image changes is directly related to the
smoothness of the motion depicted by the display. Although display
of the terrain image is particularly useful to the aircraft crew
during flight, it also is useful during take-off, landing and
taxiing collectively referred to as when the aircraft is proximate
the surface of the earth.
[0021] The image database 102 contains information used to generate
an overlay image depicting objects (animate or inanimate) with
various levels of details that denote operational parameters of the
aircraft and is similar to databases used for previous primary
flight displays. The display processing engine 106 receives data
from the external data sources indicating the status of aircraft
operational parameters, such as speed, altitude, roll and pitch.
The aircraft operational parameters and information from the image
database are used by the display processing engine 106 to generate
a second display signal that represents the overlay image
containing graphics that indicate the present operating status of
the aircraft.
[0022] The overlay image then is superimposed over the underlay
image to produce a display image for presentation on the display
device 108. The result of this image processing is a combined
display signal on path 1 10 from the display processing engine 106.
The combined display signal can be digital and/or analog in the
form of electrical signals, infrared signal, optical signals or any
other type of signal that can be converted by a display device to
depict images.
[0023] The combined display signal representing the display image
is applied to an image processor 110 which converts that signal to
be compatible with one or more formats (or protocols) commonly used
by display devices. Image processor 110 performs a function similar
to a symbol generator circuit that is typically used by display
devices to generate images; that is, the display signals are
converted to a VGA (Variable Graphics Array) signal or a RGB (Red,
Green and Blue) signals or any other well known analog and/or
digital signals typically used to generate images on a display
device. The resultant display signal from the image processor 110
is routed onto path 120 for reception by the display device 108
that has a display screen 109 on which the image is displayed.
[0024] FIG. 3 depicts an exemplary display image 130 that is
presented to the pilot on the display screen 109 of device 108 as a
result of the processing performed by the display generation system
101. Preferably, the image is in color to provide greater contrast
among the objects contained in the display image. The exemplary
terrain 120 depicted in the display image 130 illustrates a
mountain in front of the aircraft with the horizontal, or zero,
pitch line 122 passing through the mountain just below its peak
124. Associated with the terrain image 120 are two pitch scales 124
and 126 extending vertically on the left and right sides. Each
pitch scale contains L-shaped degree markers above and below the
zero pitch line 122 indicating five degree increments with the
corresponding numbers designating the 10 and 20 degree markers.
Each pitch scale 124 and 126 is non-linear in that the spacing
between adjacent five degree markers decreases going farther away
from the zero pitch line 122. In other words, the distance between
the zero pitch line 122 and each 10 degree marker is greater than
the distance between the 10 degree marker and the 20 degree marker,
even though those distances correspond to the same number of
degrees on the scale.
[0025] As noted previously with respect to the conventional PFD in
FIG. 1, the standard pitch ladder used on those previous displays
had a linear scale in that there was the same distance between
marks on the scale corresponding to identical degree increments.
However, using readily available topographical data with standard
terrain generation techniques produces terrain images that do not
correspond to a linear, or uniformly spaced, pitch scale. As a
consequence, simply superimposing a conventional linear pitch scale
over the terrain image results in an inaccurate relationship
between motion of the terrain image and the pitch indicators as the
aircraft climbs and descends. Therefore, the pitch scales 124 and
126 are non-linear and have gradations that match relationship of
the terrain image to aircraft pitch.
[0026] The display image 130 on the display screen also contains
several graphical objects 132, 134, 136 and 138 which indicate
operational parameters of the aircraft. Those graphical objects are
formed by the display processing engine 106 from operational data
received through the data ports 116 and information from the image
database 102. In the exemplary display image 130, a first graphical
object 132 corresponds to a standard speed tape indicating the
speed of the aircraft and a second graphical object 134 is a
heading tape. The third graphical object 136 is an altitude
indicator, while the graphical object 138 indicates vertical
speed.
[0027] With reference to FIG. 4, as the aircraft pitches downward,
such as during a descent, the terrain image 120 rises on the
display screen. The two pitch scales 124 and 126 also move upward
the same amount as the terrain image. Note that the minus 30 degree
marks now appear near the bottom of the terrain image and are
spaced much closer to the 20 degree marks than the 20 degree marks
are spaced with respect to the 10 degree marks, further denoting
the non-linear relationship of aircraft pitch to the terrain image.
A similar opposite motion of the terrain image and the pitch scale
occurs as the aircraft climbs.
[0028] Alternatively, a linear pitch scale could be utilized in
which case the display processing image 106 would morph, or
distort, the terrain image in the vertical dimension in order for
the terrain image to correspond to the linear pitch scale.
Nevertheless, there is a limit to the amount of morphing which is
practical before the terrain image no longer accurately represents
the actual terrain appearing through the window of the aircraft and
becomes so distorted as to be disconcerting to the pilot.
[0029] The foregoing description was primarily directed to a
preferred embodiment of the invention. Although some attention was
given to various alternatives within the scope of the invention, it
is anticipated that one skilled in the art will likely realize
additional alternatives that are now apparent from disclosure of
embodiments of the invention. Accordingly, the scope of the
invention should be determined from the following claims and not
limited by the above disclosure.
* * * * *